Is there any truth to the claim that vegans live longer?

Yes! It’s been shown that increased life expectancy occurs in parts of the world where diet is predominately vegetarian or vegan based - compared to countries where meat-based protein is the favoured option.

Soya-bean curd or tofu as it's also known has been proven to lower cholesterol. It's also been shown that a healthy vegetarian or vegan (one who's getting all their nutritional needs met) tend to live longer than meat eaters. Obviously this is within the context of adopting a healthy lifestyle.